Ulan-Ude, the capital of Buryatia, is located at the foot of the mountains and is divided into two parts by the Uda river, a tributary of the Selenga river. It is the third largest city in East Siberia. Ulan-Ude, former Verkhneudinsk, was founded in 1666 by Russian Cossacks. Due its geografical position the city grew rapidly and became a large trade centre which connected Russia with China and Mongolia. There are old merchants' mansions richly decorated with wood and stone carving in the historical center of Ulan-Ude along the river banks. They represent beautiful examples of Russian classicism.